Microphone



Jam 5,'1926.

' l.. DARIMONT MICROPHONE Filed Oct. 4, 1924 m 6v @D INVENTQA LBDPCLLID :HRI'IIDNT URNEY Patented J an. .1926..

LOPOLD DARIMONT, OF BRUSSELS, BELGIUM.

MICROPHONE.

Application medoc/ober 4,1924. serial No. 741,661.

To all whom 'it may concern:

'Be it known that I, LoroLD DARIMONT,

a subject of the Kin ,of the Belgians, and` resident of Brussels, el ium, have invented certain new and usefu Improvements in Microphones, of which the following is a specification. y

My present invention has for its object a useful improvement in microphones for telephonie plants, and more particularly in microphones wherein the vlbrations of a vibrating late are transmitted by means of balls of iii'erent sizes arranged between the two poles, the whole being enclosed within a suitable housing. The-said improve-` ment consists of such an larrangement of the balls that the large balls arranged between the poles ,form constant contacts between them, whilst the small balls or grains are arranged in the interstices between the large balls and of such sizes that they will be completely movable in said interstices, said arrangement producing two dierent elects of variation of resistance in the michophonic circuit which will be produced simultaneously and therefore added to each other to permit the transmission of vocal vibrations and musical vibrations simultaneously, that is the natural transmission of thel humanl voice.

One embodiment of my invention is illustrated by way of example in axial longitudinal section in the accompanying drawhe improved microphone comprises a suitable housing or casing, such as cylinder 1 made of Celluloid, which contains the two poles 2 and 3, made of carbon or any other" suitable material.- i

The pole 2 is attached to the base 1L of the cylinder and surrounded by a conducting wire 2EL extending through said cylinder. The pole 3 is attached to a screw-threaded bolt or rod 5 screwed into the base 1" of the cylinder and provided with a key-slot 5*i to enable the pressure produced between the two poles to be adjusted. Said rod isalso provided with a nut 5 serving to attach the conducting wire 5b and hold the pole 3 1n its adjusted position. Arranged between the poles 2 and 3 are balls of carbon or any other suitable material. Said balls are of different sizes: the larger ones 6 are placed directly between the two poles. and -form constant contacts between them. Arranged in the interstioes between them are smaller balls or grains 7 and 7, the diameter of which is'such that they willlbe freely movt able in said interstices. The whole, .namely the cylinder, poles 2 and 3, balls 6, 7 and 7a etc., form one unit which may be set into contact with any vibratory material to reveal the vibrations thereof, and in the present example, the sameis attached directly or by means of an intermediate part 1c to a vibrating plate 8.

Said vibrating plate is held in a suitable protectin casing 10 by means of rings 9 and 9, the w ole being assembled and attached by means 4of a screw-threaded ring 11 screwed onto the part 10, whilst the opposite end of the casing is closed by means of a cover-plate 12 screwed onto the-part 10d.

The conducting wire 2a extends through the casing at 10 Where insulating material is provided to this end, whilst the conducting wire 5a is soldered to the casing at 102l and phonio circuit of the device described aredue to two different effects of sensitiveness,

which' will be Vroduced simultaneously and the results of w ich will be added. The first eii'ect is due tothe arrangement of large balls forming constant contacts l between them, whichresults in the possibility of the transmission of the voice. The second eHect is due to the jolting of the movable grains in the interstices between the large balls. Said jolting produces Very sharp variations in the coherence between said small balls or grains and said large balls, which produces a second series -of variations in the microphonic circuit more intensive and particularly more abrupt permitting the transmission of musical vibrations, whereas the same would not be convenient for the transmission of. Vocal transmissionstowing to said too sudden-vibrations). The two effects will be produced simultaneously and the results thereof will be added. The final result thereof will be the transmission of the voice with all itstones, whereby it will be rendered natural.

be secured to the` The microphonic c linder forming a unit may be used for amp ifying-` the scarcely revealable vibrations in wireless telegraphy at the receiving stations b applying the same at the place where sai vibrations are produced. It is obvious that constructional modications may be made in the microphone described without departing from the scope of the invention. I may for instance combine several units and arrange the same either side by side or one above the other, and the cylinders l may be placed upon the vibrating plate in any other convenient manner.

Having now :fully described my said invention, what I claim and desire to secure by Letters Patent, is:

1. In a microphone, the combination with a suitable container, and poles arranged at opposite ends thereof, of a plurality of large balls placed directly between said poles and forming constant contacts between them, a pluralityv of small balls or grains laced in the interstices betyveen said large alls and freely movable therein, and suitable connections to any desired telephonie circuit, substantially as set forth.

2. In a microphone, the combination with a suitable container, poles arranged at opposite ends thereof, and means for adjusting one of said oles of a pluralit of large balls placed directly between sai poles and forming constant contacts between them, a plurality of smallballs or grains laced in the interstices between said large balls and freely movable therein, and suitable connections to any desired telephonie circuit, substantially as set forth.

In testimony whereof I have hereunto set my hand.

LEOPOLD DARIMONT. 

